7 citations · 7 across the 5 of their papers we have counts for
8 papers
Induced quadratic modules in -algebras
Jaka Cimpric, Yurii Savchuk
Positivity in -algebras can be defined either algebraically, by quadratic modules, or analytically, by -representations. By the induction procedure for -represent…
On structure of homogenenous Wick ideals in Wick -algebras with braided coefficients
Vasyl Ostrovskyi, Danil Proskurin, Yurii Savchuk +1
We study the structure of Wick homogenenous ideals of higher degrees in quadratic algebras allowing Wick ordering. We present a method how to construct a homogeneous Wick ideal $\m…
On -normal operators and quantum complex plane
Jaka Cimpric, Yurii Savchuk, Konrad Schmüdgen
For let $\cA$ denote the unital -algebra with generator and defining relation . Based on this algebra we study -normal operators, the complex $…
Positivstellensätze for Algebras of Matrices
Yurii Savchuk, Konrad Schmüdgen
The paper is concerned with various types of noncommutative Positivstellensätze for the matrix algebra $M_n(\cA)$, where $\cA$ is an algebra of operators acting on a unitary space,…
A noncommutative version of the Fejér-Riesz theorem
Yurii Savchuk, Konrad Schmüdgen
Let $\cX$ be the unital *-algebra generated by the unilateral shift operator. It is shown that for any nonnegative operator $X\in \cX$ there is an element $Y\in \cX$ such that $X=Y…
Unbounded Induced Representations of *-Algebras
Yu. Savchuk, K. Schmuedgen
Induced representations of -algebras by unbounded operators in Hilbert space are investigated. Conditional expectations of a -algebra $\cA$ onto a unital -subalge…